SPI without Pin 10

Projects Networking, Protocols, and Devices
2

SPI supports multiple devices in parallel, each needs its own CS output.
Pin 10 Must be an output for the uC to be the SPI master.
So you can have:

digitalWrite (pin10, LOW);
SPI.transfer(data1);
digitalWrite (pin10, HIGH);

digitalWrite (pin8, LOW);
SPI.transfer(data2);
digitalWrite (pin8, HIGH);

to transfer data out to 2 different devices, with SCK and MOSI going to both in parallel, and pin8 and pin10 being the control of whether device does something with the data or not.